Producing slotted material



p 1968 I R. .1. KlNKAlD 3,402,590

PRODUCING SLOTTED MATERIAL Filed Aug. 11, 1965 United States PatentOflice 3,402,590 PRODUCING SLOTTED MATERIAL Robert John Kinkaid, NewCumberland, Pa., assignor to AMP Incorporated, Harrisburg, Pa. FiledAug. 11, 1965, Ser. No. 478,811 Claims. (Cl. 72-330) ABSTRACT OF THEDISCLOSURE Slotted material is produced with a section of material beingformed by the use of a blanking die to form a substantially triangularor diamond-shaped area, legs are blanked from the triangular ordiamond-shaped area by a triangular or diamond-shaped blanking die withthe legs extending outwardly from each other from one end in the case ofthe triangular-shaped area and from both ends in the case of thediamond-shaped area, and the legs are forced toward each until they aresubstantially parallel thereby forming a slot less than or equal to thethickness of the material.

This invention relates to an apparatus and a method of forming a narrowslot in material.

It is a standard practice in the metal blanking art to use punches atleast one and a half times in width than the thickness of the materialthey are to penetrate. If the thickness of the material to be blankedexceeds the desired slot width, it becomes impractical to produce thisWidth of slot, because the punches to blank the slot are incapable ofperforming such an operation in accordance with standard blankingpractice.

It is a primary object of the invention to form a narrow slot inmaterial.

Another object of the invention is to form a narrow slot in materialhaving a thickness greater than the width of the slot.

A further object of the invention is to form a slot having an open endand a slot having closed ends in material.

An additional object of the invention is to provide means to form anarrow slot in material.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon a reading of the followingdetailed description when taken in conjunction with the drawings inwhich there are shown and described illustrative embodiments of theinvention; it is to be understood, however, that these embodiments arenot intended to be exhaustive nor limiting of the invention but aregiven for purposes of illustration in I order that others skilled in theart may fully understand the invention and the principles thereof andthe manner of applying it in practical use so that they may modify it invarious forms, each as may be best suited to the conditions of aparticular use.

The foregoing objects are realized in the case of an open end slot bystamping the material to form a section having a substantiallytriangular configuration, removing a triangular portion of thetriangular section to form a bifurcated section and forcing legs of thebifurcated section together to form a slot having the desired width. Inthe case of forming a slot in material having closed ends, the materialis subjected to a blanking operation to form a section having asubstantially diamond configuration, a diamond-shaped piece is blankedfrom the diamondshaped section and opposite legs on respective sides ofthe apices are engaged to push the legs together thereby forming thenarrow slot.

In the drawing:

FIGURE 1 is a perspective, exploded and partially sectioned view showinga progressively formed electrical connector member;

Patented Sept. 24, 1968 FIGURE 2 is a view taken along lines 2-2 of FIG-URE l; and

FIGURE 3 illustrates the formation of a narrow slot having closed ends.

The present invention is described in conjunction with the formation ofelectrical connector members and forming in the contact end of theelectrical contact members a narrow slot to form a contact end having abifurcated configuration; however, it is to be understood that where itis essential to form a narrow slot in material, the present invention isapplicable thereto. Thus, a practical use of the invention is inbifurcating the contact sections of electrical connectors. Bifurcationdoubles the number of contact surfaces at each connection, and thereliability of the electrical connector is substantially increased overthat of an electrical connector having a contact section provided with anon-bifurcated contact section.

Turning now to the drawings and more particularly FIGURES 1 and 2, thereis illustrated a sheet of metal 1 moving in the direction indicated byarrow 2 between blanking dies of a conventional blanking machine whichhas not been illustrated for purposes of simplicity. As can bediscerned, sheet of metal 1 has been premilled to form a section that isthinner than the other section.

As sheet of metal 1 is being moved between the stamping dies of thestamping machine, blanking dies engage the sheet of metal at the variousstations along the progressive die to blank out metal from the sheet ofmetal as well as to form the sheet of metal into the desirableconfiguration. As illustrated, sheet of metal 1 is blanked to form anelectrical connector of the type illustrated in applicants co-pendingUS. patent application Ser. No. 349,565, filed Mar. 5, 1964, nowabandoned. Electrical connector 3 is formed to include a conductorreceiving section 4 in the thickest section of the sheet of metal 1 anda contact section 5 in the thinner section of the metallic sheet.Contact section 5 is first formed at the initial blanking station as asubstantially triangularshaped section 6. At the next blanking station,a triangular-shaped punch 7 engages triangular-shaped section 6 andblanks therefrom a piece of metal conforming in configuration to that ofpunch 7 and forming legs 8 which are directed away from each other fromone end of the legs.

A forming punch 9 is disposed at the next station in line and includes amouth 10 having tapered surfaces 11 which merge with parallel surfaces12. Forming punch 9 is moved downwardly toward legs 8 from the innermostportion of contact section 5 to about the mid-portion thereof. Duringthe downward movement of forming punch 9, tapered surfaces 11 engagelegs 8, and move along tapered surfaces 11 and parallel surfaces 12 asillustrated in FIGURE 2. This causes legs 8 to move toward each otherand reach a final position wherein they are disposed parallel orsubstantially parallel with respect to each other and forming a slot 13therebetween. At the next station, bifurcated contact section 5 isformed into a spoon-shaped configuration and the formed connectors canbe sheared from metallic sheet 1 or left in strip form as desired.

The invention is useful in forming narrow slots in material wherein thewidth of the slots is less than or equal to the thickness of thematerial. If punching dies having a thickness less than or equal to thatof the material upon which they are to operate are used to form slotstherein, the life expectancy of the punching dies will be very short andthe cost of replacing the punching dies will be prohibitive. The presentinvention obviates this drawback by using a blanking die in one stationto blank out material from the section in which a narrow slot having awidth less than or equal to the thickness of the material is to beformed so as to form legs which are directed outwardly fromeach other inaccordance with an angular disposition determined by the punching die,the legs then being shoved toward each other by means of a forming punchuntil the legs are disposed substantially in parallel relationship toform the narrow slot. The apex of triangularshaped punch 7 is radiusedso as to conform to the width of the slot. It is obvious that thepresent invention can be applied to other electrical connectors whereinthe contact section is to have a bifurcated configuration.

FIGURES 1 and 2 are directed to forming a bifurcated contact sectionwherein the ends of legs 8 at one end of the slot are free. FIGURE 3illustrates a bifurcated contact section 5 wherein slot 13 is closed atboth ends. In this embodiment, section 14 in which the slot is to bemade is initially formed in the shape of a substantially diamondconfiguration. Next, a diamond shaped blank is stamped out of thediamond-shaped section by means of a diamond-shaped punch similar tothat of punch 7 leaving outwardly directed legs extending outwardly fromboth ends of legs 8' as illustrated in phantom in FIGURE 3. A formingdie, similar to forming die 9, is then used to squeeze legs 8 togetheruntil slot 13' is formed having closed ends. The outer ends of thediamond-shaped punch are radiused to conform to the width of slot 13'.Bifurcated contact section 5' may be formed with one end havingextensions extending outwardly to engage projections in a housing memberto limit the movement of the contact section into the contact area ofthe housing member.

As can be discerned, there has been disclosed a unique method andapparatus for forming narrow slots in material wherein the width of theslots is less than or equal to the thickness of the material in whichthe slots are to be formed and the slots may have one end opened or bothends of the slots may be closed.

It will, therefore, be appreciated that the aforementioned and otherdesirable objects have been achieved; however, it should be emphasizedthat the particular embodiments of the invention, which are shown anddescribed herein, are intended as merely illustrative and not asrestrictive of the invention.

What is claimed is:

1. A method of forming a narrow slot in a sheet of material with theslot having a width less than or equal to the thickness of the sheet ofmaterial comprising the steps of feeding the sheet of material betweendie members defining blanking stations therealong, blanking the sheet ofmaterial at the blanking stations to form a member having a planarsection, removing part of the planar section thereby forming leg membersextending away from each other at an acute angle from one end thereof,and moving said leg members toward each other until they aresubstantially parallel to each other whereby said narrow slot is formedtherebetween.

2. A method of forming a narrow slot in a sheet of material with theslot having a width less than or equal to the thickness of the sheet ofmaterial comprising the steps of feeding the sheet of material betweendie members defining blanking stations therealong, blanking the sheet ofmaterial at the blanking stations to form a member having a planarsection, removing prat of the planar section thereby forming leg membersextending away from each other at an acute angle from one end thereofwith the other ends thereof being free, and moving said leg memberstoward each other until they are substantially parallel to each otherwhereby said narrow slot is formed therebetween.

3. A method of forming a narrow slot in a sheet of material with theslot having a width less than or equal to the thickness of the sheet ofmaterial comprising the steps of feeding the sheet of material betweendie members defining blanking stations therealong, blanking the sheet ofmaterial at the blanking stations to form a member having a planarsection, removing part of the planar section thereby forming leg membersextending away from each other at an acute angle from each end of theleg members, and moving said leg members toward each other until theyare substantially parallel to each other whereby said narrow slot isformed therebetween.

4. A method of forming a narrow slot in a sheet of material with theslot having a width less than or equal to the thickness of the sheet ofmaterial comprising the steps of feeding the sheet of material betweendie members having blanking stations therealong, blanking the sheet ofmaterial at the blanking stations to form a member having a planarsection of substantially triangular configuration, removing a triangularpiece of material from the planar section thereby forming leg membersextending outwardly from each other from one end of said leg members,and moving the leg members toward each other until they aresubstantially parallel whereby said narrow slot is formed therebetween.

5. A method of forming a narrow slot in a sheet of material with theslot having a width less than or equal to the thickness of the sheet ofmaterial comprising the steps of feeding the sheet of material betweendie members ha ving blanking stations therealong, blanking the sheet ofmaterial at the blanking stations to form a member having a planarsection of substantially diamond configuration, removing adiamond-shaped piece of material from said planar section therebyforming leg members extending outwardly from each end of said legmembers, and moving said leg members toward each other until they aresubstantially parallel whereby said narrow slot is formed therebetween.

6. An apparatus for forming a narrow slot in a sheet of material withthe slot having a width less than or equal to the thickness of materialcomprising blanking-die means for operating on said sheet of material toblank out a member having a planar section, one of said blanking-diemeans being of a configuration to blank out a piece of material fromsaid planar section thereby forming leg members of said planar sectionwith the leg members extending outwardly from each other at an acuteangle from at least one end thereof, and a forming-die means having amouth for receiving said outwardlyextending leg members within saidforming-die means and surfaces for engaging said outwardly-extending legmembers and moving said outwardly-extending leg members toward eachother until they are substantially parallel whereby said narrow slot isformed therebetween.

7. An apparatus according to claim 6 'wherein one end of said one ofsaid blanking-die means has a radius conforming to the width of thenarrow slot.

8. An apparatus for forming a narrow slot in a sheet of material withthe slot having a width less than or equal to the thickness of materialcomprising blankingdie means for operating on said sheet of material toblank out a member having a planar section of substantiallytriangular-shaped configuration, one of said blanking-die means beingtriangular-shaped for blanking out from said planar section a triangularpiece of material thereby forming leg members of the planar section withthe leg members extending outwardly from each other at an acute anglefrom one end thereof, and a forming-die means having a mouth forreceiving said outwardly-extending leg members within said forming-diemeans and surfaces for engaging said outwardly-extending leg members andmoving said outwardly-extending leg members toward each other until theyare substantially parallel whereby said narrow slot is formedtherebetween.

9. An apparatus for forming a narrow slot in a sheet of material withthe slot having a width less than or equal to the thickness of materialcomprising blanking-die means for operating on said sheet of material toblank out a member having a planar section of substantiallydiamond-shaped configuration, one of said blanking-die means beingdiamond shaped for blanking out from said planar section adiamond-shaped piece of material thereby forming leg members of saidplanar section with the leg members extending outwardly from each otherat an acute angle from each end thereof, and a forming-die means havinga mouth for receiving said outwardly-extending leg members within saidforming-die means and surfaces for engaging said outwardly-extending legmembers and moving said outwardly-extending leg members toward eachother until they are substantially parallel whereby said narrow slot isformed therebetween.

10. An apparatus according to claim 9 wherein opposite ends of said oneof blanking-die means have a radius conforming to the width of thenarrow slot.

References Cited UNITED STATES PATENTS Weaver 72337 Skelton 72332Johnston 72-325 Conner 72-338 Berg 29-l55.55

10 CHARLES W. LANHAM, Primary Examiner.

E. M. COMBS, Assistant Examiner.

